A7A7
技術範圍 發明係屬於放大器及比較器之差動輸入 別者係屬认JL古扯仅f、认 响于义保4及特 可你屬於具有被保濩 < 輸入端子之_差動放大哭。 發明背景及技藝現狀 許多實較用包含-運算放大器之電路,此種放大 於回饋之使用及一運算放大器之增益爲甚高之一事實,其 =輸入端子間之電壓普通甚爲接近於零値。比較下,、設^ :比較器爲提供一代表比較器上二輸入端子間電壓之輸出 仏唬,-電路在正常使用下,通常總是在比較器之輸入端 子間存有某些電壓。無論如何,輸人之電壓由於外部提供 至輸入端子之信號變爲甚大甚至能破壞比較電路。如果用 於—運算放大器之回饋未適當運作,如果提供之輸入電壓 過大時此種放大器可能被破壞。在同一時間回饋不運算之 原因可能爲一較大之電壓提供至輸入在運算放大器輸出端 子上得出如“過量率,,限制之故,或運算放大器之輸出端子 被接至一很高之負載。因之用於運算放大器及特別是比較 斋一者均需一保謾電路。在慣常之電路中在輸出端子間一 限制之機制及者顯然尚未設有。 發明摘要 本發明之目的爲對一差動型放大器之輸入端子提供一簡 單及有效之保護。 一差動型電晶體基極之放大器之二個輸入端子,此處認 爲按慣常方式,活動之放大電晶體以基極端子爲輸出。輸 入電晶體中基極-射極-連接由被連接成如其射極及基極相 -4- 本紙張尺度適用中國國家標準(CNS)A4規格(21〇 x 297公釐) ------------#·裝 (請先閱讀背面之注意事項再填寫本頁) 訂--------- 經濟部智慧財產局員工消費合作社印製 經濟部智慧財產局員工消費合作社印製 478230 A7 B7 五、發明說明(2 ) 互連接一起之"一二極體之電晶體來保護。活動電晶體中活 動之PN -接面爲基極與集極之連接與在反面向之基極與射 極間P N -接面正常下有較高之破壞擊穿電壓。译護之電晶 體可有效的做成如輸入電晶體之相同方式及具有完全相同 之電氣特性及其簡單來引用於電氣積體電路中之保護上。 如此,一般差動型放大器可認爲包括二放大電晶體,放 大器之輸入端子直接連接至每一放大器電晶體之基極用於 接收輸入電壓r,所產生及/或放大之差即如在一放大器輸出 端子上所獲得之輸出電壓。如此輸出電壓則代表輸入端子 間之電壓。最好,輸出端子直接連接至放大器電晶體之一 ' 之集極上。 對輸入端子及特別是防止流過放大電晶體過程之電流之 保護,保護之二極體直接與一第一電晶體之射極成串聯連 接。每一保護之二極體成具有相同之方向或極性者相連接 如同由電晶體其所連接而形成之基極與射極間P N -接面, 近爾,保護之二極體由保護之電晶體來.形成,且其射極及 基極相互直接電氣連接。 一般將不使用各稱之“射極”及“集極”,直接與每一放大 器電晶體中被連接之一保護之二極體相反方向具有最低之 破壞擊穿電壓之P N -接面之一成串聯,該一被連接之一保 護之二極體相反方向如同由具有最低破壞擊穿電壓之第一 電晶體之P N -接面所形成之二極體具有相同方向或極性。 每一個保護二極體毒括一個相同極性型如同放大器電晶體 之保護電晶體,差動放大器中該保護之二極體一般爲完全 -5- 本紙張尺度適用中國國家標準(CNS)A4規格(210 X 297公釐) (請先閱讀背面之注意事項再填寫本頁) I裝 ----訂---------. 478230 A7 B7_ 五、發明說明(3 ) (請先閱讀背面之注意事項再填寫本頁) 相互相似或最少具有完全相似之電氣特性或性質。每一保 護之電晶體中每一第一及第二PN -接面在由一直接電氣連 接被短路情形下反向方具有最低之破壞擊穿電壓。 放大器電晶體及保護之電晶體均為完全相同類之NPN電晶 體或均為完全同類之PNP電晶體。 圖面重點說明 發明將對不應受限制之具體實施例及配合附屬之圖面加 以說明之,其中: 圖1為一先前已知型一單一電晶體基極之差動放大器之一 電路圖, 圖2為圖1之放大器簡化之電路圖其中僅示出一些必要之 元件, 圖3為一垂直之NPN電晶體之圖示之截面圖, 圖4為先前已知之具有保護之輸出端子之一差動放大器之 電路圖, 圖5 a為一電晶體與一二極體間相等之一圖面,其中電晶 體之基極與集極直接相互電氣連接, 圖5 b為顯示一電晶體基極與射極為直接相互電氣連接與 二極體間相等之圖面, 經濟部智慧財產局員工消費合作社印製 圖6 a為按照圖2具有輸入端子保護之一放大器電路圖, 保護由電晶體連接如二極體而護得, 圖6 b為與圖6 a相似對於另外特性之電晶體之電路圖,及 圖7為按照圖1具有輸入端子之相同保護如圖6 a所示之一 放大器電路圖。 -6- 本紙張尺度適用中國國家標準(CNS)A4規格(210 X 297公釐) 478230 A7 B7 五、發明說明(4 ) 所選具體實施例之説明 (請先閱讀背面之注意事項再填寫本頁) 以下爲對元件之極性有一些限定之一放大器電路之説 明。很明顯的對於精於此一技藝之士言放大器電路可使用 相反之極性使得NPN電晶體可以由PNP電晶體來代替,及反 之亦然,二極體之方向可相反,正電壓可變爲負電壓,反 之亦然,而電流亦可相反等,除非使用之元件另有考慮則 應具有相符及相同之電氣性質。 圖1中,示出輸入伋一普通形式之電路圖,輸入仪顯示適 v 合用於例如比較器或運算放大器之一差動放大器。電路之 二輸入端子1,3由二個相似之例如示於圖1中NPN-型電晶 體T 1及T2之基極端子組成。電晶體T 1及T2之射極相互連‘ 接至一射極點5並連接至由一適當之電壓工作如同一電流電 源之一第三NPN電晶體T 3之基極及藉此提供一射極電流至. 輸入電晶體T 1及T 2。第三電晶體之射極如圖所示可接至某 一供給電壓V EE,舉例如較接地電位爲其小偏置之一負電壓 或其自己之接地電位。 經濟部智慧財產局員工消費合作社印製 特大放大之電晶體或輸入電晶體之二第一電晶體T 1及T 2 之集極,一適當方式,如圖示之例經一電流鏡像電路,連 接至例如一正定値電壓之供給電壓V cc。電流鏡像電路包括 二PNP電晶體T4及T5,其基極相互直’接連接及其射極連接 至供給電壓V π。用於第一輸入電晶體T 1之PNP電晶體T 4 尚具有其基極與集極相互連接使得其工作如同一二極體, 但是,此二電晶體T 4及T 5具有其基極耦合至各別之輸入電 晶體T 1及T 2之集極上。重要之事實,與輸入電晶體T 1及 本紙張尺度適用中國國家標準(CNS)A4規格(210 X 297公釐) 478230 A7 B7 五、發明說明(5 ) (請先閱讀背面之注意事項再填寫本頁) T 2相匹配連至驅動電壓V cc之電晶體T 4及T 5具有相同之阻 抗及閑時或無負載電壓(載維寧等效)使得輸入電晶體T 1及 T 2得以在其活動區域内工作,即,在不飽和下及由其集極 至其基極之電壓一直保持為正值。园此,電流鏡像電晶體 T 4及T 5可由電阻耦合至電晶體之集極與正供給電|V⑺之 間來代替。 一輸入伋簡化之具體實施例,部分有系統的及僅包括文 中主要之元件示出如示於圖2,此處電晶體T 3為一電流產 生器I 1,另一方面輸入電晶體T 1及T 2之集極僅接至如所 示之一般指示之節點。 示於圖1及圖2之二電路輸出信號原則為經輸入電晶體 T1,T2之任何一個之集極電流。一代表此一電流之電壓舉 例可為在第二輸入電晶體T 2之集極電極之端子7流出或流 入之電流。 經濟部智慧財產局員工消費合作社印製 當輸入端子1,3間之電壓為一低值時,二輸入電晶體 T1,T2為活動且電流從它們的射極端流至共同射極節點5。 及流經這些電晶體之電流由電流電源I 1或電晶體T 3分別來 決定,及在其中受擾動使得較多電流經輸入電晶體使其輸 入端子即基極上有一最高之電壓。當輸入端子間之電壓變 為相當大時,相當大意謂電壓約為等於V τ,此處V τ正比於 絕對溫度,及V τ在室溫下約為2 6毫伏。經輸入電晶體之電 流,其輸入端子有最低之電位。可予以忽略及基極或輸入 其他輸入電晶體之輸入端子之電位由此一電晶體之飽和電 流值來定決。此一電晶體之基極與射極間之電壓在飽和約 •8- 本紙張尺度適用中國國家標準(CNS)A4規格(210 X 297公釐) 經濟部智慧財產局員工消費合作社印製 478230 A7 B7_ 五、發明說明(6 ) 在vBE=v r · logd/is),此處I i為電流產生器11所產生之電 流及I s為電晶體之飽和電流。 假設現在當在第一輸入電晶體T 1之第一輸入端1之電壓 為一甚低之值時,第二輸入電晶體T 2之輸入端子3上之電 流保持於定值。經第一輸入電晶體T 1之電壓將被再減低一 直至由電流產生器I 1及輸入電晶之飽和電流I s之電流來決 定之射極節點之電壓。當電壓進一步減低時,第一輸入電 晶體T 1中基極與射極間P N -接面將順向偏壓至一甚小及甚 小範圍以便成一反-偏置。當電壓最後變為負時,電流將再 次流經第一輸入電晶體之射極但現在為一相反之方向且依 該P N -接面之破壞擊穿電壓所超過之值而定,然後所有此 一電流經第一輸入端子即,第一輸入電晶體T 1之基極流 出。此時電流不再由電流電源I 1來決定,而由外部電壓電 源驅動容晶及二輸入電晶體T 1及T 2之電阻值來決定。在 任何情況,電流能破壞二輸入電晶體T 1,T 2但可能其中 起始之第一電晶體T 1其所導致之電能變為最大。一 NPN電 晶體之電壓在反-偏置之P N -接面間在其射極與基極間因不 同製造程序及不同元件規劃中而有不同之導通電流變化。 對信號處理之電晶體一般此電流較約6伏為高及較約1 0伏 為低。 通常,一雙極電晶體包括有成一排列相互定位之三個區 域且經常包括相互在頂部設置之層,由半導體材料製造成 具有交換之極性,使得存有一中間層區域及二個外部區 域。一雙極電晶體可能為NPN型或PNP型。自每一區域提供 _9_ 本紙張尺度適用中國國家標準(CNS)A4規格(210 X 297公釐) ------------------訂 *-------- (請先閱讀背面之注意事項再填寫本頁) 478230 A7 B7_ 五、發明說明(7 ) (請先閱讀背面之注意事項再填寫本頁) 有亦稱之謂電極之電路連接。中間區域稱之謂基極及二外 部區域各別稱之謂射極及集極。如果NPN電晶體端子所加 之電壓使得NPN電晶體為V。> Vb > Ve及對PNP電晶體及得V ( < Vb < Ve。此處V。’ Vb ’ Ve為電晶體各個之集極,基極,射 極之電位,送至基極之電流不太大時對一 NPN電晶體應為 正及對一 PNP電晶體應為負,流經電晶體之集極電流受送 至基極電流值控制。概略說,集極電流正比於基極電流。 正比之常數稱B F,“正向電流增益”以0示之。 武斷說,雙極之電晶體之二外部區域之一稱之謂射極而 另一區域為晶體之集極。無論如何,平常集極及射極被限 定使得正比之常數/3變為越大越好。對所加之電壓為同一 極性,如電晶體反轉使得集極定位於原射極定位之處,亦 可測得一相符之正比常數或電流增益因數,“反向電流增 益”。通常B F較B R為大。此一事實受電晶體之架構或規劃 之數種選取有關,此種選取考慮之中為要求BF具有越大越 好,即獲得增益可能應為最高之值。B R之值較不重要,一 般BF值= 50-100及BR=0.5-10。重要一點注意者為在放大電 路中在明顯之情況下使用一電晶體電流之增益應較1為 大。 經濟部智慧財產局員工消費合作社印制衣 積體電路中一 NPN電晶體一較普通之具體實施例為一垂 直式電晶體’如圖3顯示之橫截®示出圖。一些外部材料 1 1具有相同如基極型之低摻雜,提供層以形成電晶體之部 分或區域。集極1 3為最下層具有與外層材料相反之摻雜。 最下層之中間定位有另一層15形成基極,在基極區域中間 -10- 本紙張尺度適用中國國家標準(CNS)A4規格(210 X 297公釐) 經濟部智慧財產局員工消費合作社印製 478230 A7 B7_ 五、發明說明(8 ) 尚定位有層1 7形成射極,使得中間獲得之架構次序由底部 向上包含集極,基極及射極。不同之區域其外部端向上達 至架構之表面用做外部電氣之連接。此種做成之電晶體使 得捧雜位準按射極-基極-集極之次序成遞減,即射極區域 較基極區域之摻雜為高及基極區域較集極區域之摻雜為 高。 更近者,架構之中間基極層1 5非常薄及集極層相對的較 厚。此方式提供所需之特性包括高電流增益因數B F及優良 之高頻率特性。當集極-基極-連接為一反-偏置時亦,可獲 得破壞擊穿電壓BVeb之相同特性,當射極-集極-連接為反-偏置時,變為較破壞擊穿電壓BVeb相當大之值。在製造程 序中已予以充份利用,因之集極與基極間之破壞擊穿電壓 經常為50-120伏之大小,射極-基極連接之破壞擊穿電壓 BVeb相較為6 - 1 2伏。此種使用於應用上之製造程序使該電 路能忍受較高之電壓,例如用於聲頻之放大電路,電壓轉 換器用於車輛之電子電路等之需求。 保護輸入伋之先前已知之方式如以上所述按照圖3包括在 輸入端子上連接電阻R 1,R2與電晶體T 1,T2之基極端子 成串聯,因之基極電流受限制,近爾,二極體D 1,D 2連 接至二電晶體之射極與基極之間,使得此二二極體在每一 電晶體中在一相反於基極-射極-二極體之方向導通。如此 當電晶體T 1,T 2之一之射極與基極間反向電壓超過相當 於成反並聯連接之外部二極體D 1,D 2之順向電壓時,此 順向電壓約在0.6至1伏,電流由原經各別之電晶體導通將 -11 - 本紙張尺度適用中國國家標準(CNS)A4規格(210 X 297公釐) -----------I 裝--------訂--------- (請先閱讀背面之注意事項再填寫本頁) 478230 A7 B7_ 五、發明說明(9 ) (請先閱讀背面之注意事項再填寫本頁) 代替為經外部之二極體導通。此種電路解決之優點包含保 護之元件在正常運轉中輸入仅由於增加之保護元件跨導不 受影響。此種積體電路之製造為已知,見圖5 a,當在製造 過程中僅電晶體能取得時,二極體可由一電晶體之基極與 集極相互連接而獲得之。由於在一電晶體中存有二個PN-接 面’很明顯的一元件在電晶體之基極與射極相互連接之情 況下亦可獲得一二極體之功能,見圖5 b。無論如何,此一 二極體,由於在某些應用上與由一電晶體之集極與基極相 互連接所得出之二極體來比較,使用起來有更壞之特性, 故很少被使用。 無論如何很明顯的,使用一雙極之電晶體在一非慣常之 方式中如前述而獲得一差動放大器輸入端子之保護是可能 的,如此上所提,在大部分情況,一電晶體可以得到一高 電流增益。此種應用在下文提及已非必需。 經濟部智慧財產局員工消費合作社印製 圖6a示出一差動放大器之原理電路圖,其架構完全與圖 1及圖2具有輸入端子保護之放大器相同。在圖7中示出一 更完整之電路。此一電路解決具有二個NPN電晶體,T 6, T 7,連接於輸入電晶體T 1,T 2之射極之間及共同射極節 點5之間。此電晶體具有其基極端子接至各自之射極端子 使得僅基極-集極-二極體被使用。此種連接使得放大器之 正常運轉下之射極具有較集極-基極為高之電位,即,基 極-集極為順向偏置。 如果按以前已討論相同之方法,第二輸入電晶體T 2之基 極3上之輸入電壓被保持於定值當在另一輸入端子1,即, • 12- 本紙張尺度適用中國國家標準(CNS)A4規格(210 X 297公釐) 經濟部智慧財產局員工消費合作社印製 478230 A7 B7 五、發明說明(1Q ) 第一輸入電晶體T 1中基極上之電壓慢慢減少時,接著流經 第一電晶體之電流減低至零。進一步輸入電壓電流之減低 及將在第一電晶體T 1由射極流向基極之方向之“反向方向” 流動,且現在開始流動一直至節點5與輸入端子1間之電壓 超過電晶體T 1之射極與基極間破壞擊穿電壓BVeb及保護電 晶體T 6之集極與射極間破壞擊穿電壓BVee之總和時止,一 電晶體中集極與射極間之破壞擊穿電壓可認為,即,大部 分時間,較同一電晶體中射極與基極間之破壞擊穿電壓 BVeb為大及進一步為以上所限定之同樣大小之程度如集極 與基極間之破壞擊穿電壓BVcb。按照圖4之保護之電路之解 決,當節點5與輸出端子1間之電壓超過輸入電晶體射極與 基極間之破壞擊穿電壓BVeb時,輸入電晶體T 1之電流突波 已經發生。 圖6 b為一差動放大器之主要電路圖與圖6 a相似其中取代 NPN電晶體改使用放大或活動之二元件及如保護元件。此 一電路之運作基本上與顯示於圖6a及7電路上之方式相 同。 按照圖6 a及7或圖6 b之電路解決之優點為該電路與無保 護元件之情況比較可忍受多次之較高電壓。與按照圖已知 之電路解決方式比較可存有二個優點。在已知之解決中當 保護運作時電流經過保護元件Rl,R2,D1,D2時此一非控 制之電流有過熱之結果,按照圖6 a及圖7之解決則不會。 甚而,電阻由於其自己製造處理中不適宜製造電阻之事實 及由於在電路板上電阻佔有較大面積之事實並不適合積合 -13- 本紙張尺度適用中國國家標準(CNS)A4規格(210 X 297公釐) ------------裝--------訂--------- (請先閱讀背面之注意事項再填寫本頁) 478230 第89107592號專利申請案 中文說明書修正頁(91年元月) A7 B7 j f 11 五、發明説明( 於單一鋰積體電路中。在積體電路中電阻值越大電阻越 長。既然電阻之寬度已無法因大量生產限定下其尺寸無法 變小及由於視覺之解決等無法變小、,及電阻中長度及寬度 之比來決定,電阻具有較高電阻值能較長及面積較大。 按照圖4之保護電路,電阻R 1,R2在某種情況電路尚有 未示出之其他元件使其饋送至放大電路之輸入端子產生之 電能可能變為甚大之值。 按照圖6 a,6 b及7中之電路如二極體連接之電晶體T 6及 T 7影響差動放大器之跨導。此可能有優點亦有缺點,因 之,在一些先前已知之電路中可使用電阻連接在保護電晶 體丁 6,T7之位置而減低跨導之值。 元件符號說明 1 ' 3 輸入端子 17 層 5 射極點 ΊΠ、T2、T3 電晶體 7 端子 T4、T5 電流鏡像電路 11 外部材料 T6、T7 電晶體 13 集極 -14 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐)Technical scope The invention belongs to the differential input of the amplifier and the comparator. The others belong to the JL coupe, only f, recognized by Yibao 4 and special, but you belong to the _ differential amplification with input terminals. Background of the invention and current state of the art Many circuits are more practical than circuits that include-op amps. This kind of amplification is used for feedback and the gain of an op amp is very high. Its = the voltage between the input terminals is generally close to zero. . For comparison, let's set ^: The comparator is to provide an output that represents the voltage between the two input terminals on the comparator. In normal use, the circuit always has some voltage between the input terminals of the comparator. In any case, the input voltage becomes very large due to the signal externally supplied to the input terminals and can even damage the comparison circuit. If the feedback used for the op amp is not working properly, the amplifier may be destroyed if the input voltage supplied is too high. The reason why feedback does not operate at the same time may be that a larger voltage is supplied to the input. The output terminal of the operational amplifier is such as "excess ratio, limit, or the output terminal of the operational amplifier is connected to a very high load. Because of this, a protection circuit is required for operational amplifiers and especially for comparison. Obviously, a mechanism and a limit between output terminals in conventional circuits have not been provided. SUMMARY OF THE INVENTION The purpose of the present invention is to The input terminal of the differential amplifier provides a simple and effective protection. The two input terminals of a differential transistor base amplifier, it is considered here that in the usual way, the active amplifier transistor uses the base terminal as the output .The base-emitter-connection in the input transistor is connected as its emitter and base phase -4- This paper size applies the Chinese National Standard (CNS) A4 specification (21〇x 297 mm) ---- -------- # · Installation (please read the precautions on the back before filling out this page) Order --------- Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs Consumer Cooperatives Employees of the Intellectual Property Bureau of the Ministry of Economic Affairs Printed by Consumer Cooperative 478230 A7 B7 V. Description of the Invention (2) "Diode" transistor connected to protect each other. The active PN-junction in the active transistor is the connection between the base and the collector and the base and the opposite side. The emitter-to-electrode PN-junction has a higher breakdown breakdown voltage under normal conditions. Transistors can be effectively made in the same way as input transistors and have exactly the same electrical characteristics and are simply cited in electrical products. In this way, the general differential amplifier can be considered to include two amplifier transistors, the amplifier's input terminal is directly connected to the base of each amplifier transistor for receiving the input voltage r, generated and / or The difference in amplification is the output voltage obtained at the output terminal of an amplifier. In this way, the output voltage represents the voltage between the input terminals. Preferably, the output terminal is directly connected to the collector of one of the amplifier transistors. In particular, to prevent the current flowing through the amplification transistor, the protected diode is directly connected in series with the emitter of a first transistor. Each protected diode has a phase Those connected in the same direction or polarity are connected by the PN-junction between the base and the emitter formed by the transistor, which are close to each other. The protected diode is formed by the protected transistor, and its emitter The base and the base are directly electrically connected to each other. Generally, the so-called "emitter" and "collector" will not be used, and it will directly have the lowest breakdown breakdown in the opposite direction of the diode protected by one of the connected transistors in each amplifier. One of the PN-junctions of the voltage is connected in series, and the diode protected by the connected one has the opposite direction as the diode formed by the PN-junction of the first transistor with the lowest breakdown voltage. Direction or polarity. Each protection diode includes a protection transistor of the same polarity type as an amplifier transistor. The protection diode in a differential amplifier is generally complete. -5- This paper size applies to Chinese national standards (CNS ) A4 size (210 X 297 mm) (Please read the precautions on the back before filling out this page) I Packing ---- Order ---------. 478230 A7 B7_ V. Description of the invention (3) (Please read the notes on the back before filling this page) Similar or at least have completely similar electrical characteristics or properties. Each of the first and second PN-junctions in each protected transistor has the lowest breakdown breakdown voltage when the reverse side is shorted by a direct electrical connection. Both the amplifier transistor and the protected transistor are NPN transistors of the same type or PNP transistors of the same type. The drawing emphasizes that the invention will explain specific embodiments that should not be limited and the accompanying drawings, in which: FIG. 1 is a circuit diagram of a previously known type differential amplifier with a single transistor base, FIG. 2 is a simplified circuit diagram of the amplifier of FIG. 1, which shows only some necessary components, FIG. 3 is a cross-sectional view of a vertical NPN transistor, and FIG. 4 is a differential amplifier with a previously known output terminal with protection The circuit diagram is shown in Fig. 5a, which is the same as that between a transistor and a diode, in which the base and collector of the transistor are directly and electrically connected to each other, and Fig. 5b shows that the base and emitter of a transistor are directly connected. The mutual electrical connection is the same as that between the diodes. It is printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs. Figure 6a is a circuit diagram of an amplifier with input terminal protection according to Figure 2. Therefore, FIG. 6b is a circuit diagram of a transistor with similar characteristics to that of FIG. 6a, and FIG. 7 is a circuit diagram of an amplifier shown in FIG. 6a with the same protection as the input terminal according to FIG. -6- This paper size is in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm) 478230 A7 B7 V. Description of the invention (4) Description of the selected specific embodiment (please read the precautions on the back before filling in this Page) The following is a description of one of the amplifier circuits that has some restrictions on the polarity of the components. Obviously, for those who are skilled in this technology, the amplifier circuit can use the opposite polarity so that the NPN transistor can be replaced by a PNP transistor, and vice versa, the direction of the diode can be reversed, and the positive voltage can be changed to negative. Voltage and vice versa, and current can also be reversed, unless the components used have other considerations, they should have consistent and identical electrical properties. In Figure 1, a general-purpose circuit diagram of the input sink is shown. The input meter shows that it is suitable for use in, for example, a differential amplifier such as a comparator or an operational amplifier. The two input terminals 1, 3 of the circuit are composed of two similar terminal terminals of the NPN-type transistors T1 and T2 shown in Fig. 1, for example. The emitters of transistors T 1 and T 2 are interconnected to one emitter 5 and to the base of a third NPN transistor T 3 which operates at a suitable voltage as one of the same current sources and thereby provides an emitter Current to. Input transistors T 1 and T 2. The emitter of the third transistor can be connected to a certain supply voltage V EE as shown in the figure, for example, it is a negative voltage with a small offset from the ground potential or its own ground potential. The consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs prints a very large transistor or the input of the second transistor T 1 and T 2 collectors. An appropriate method, as shown in the figure, is connected through a current mirror circuit. To a supply voltage V cc of, for example, a positive constant voltage. The current mirror circuit includes two PNP transistors T4 and T5, whose bases are directly connected to each other and their emitters are connected to the supply voltage V π. The PNP transistor T 4 for the first input transistor T 1 still has its base and collector connected to each other so that it operates as the same diode, but the two transistors T 4 and T 5 have their base coupling. To the collectors of the respective input transistors T 1 and T 2. Important facts, with the input transistor T 1 and the paper size applicable to the Chinese National Standard (CNS) A4 (210 X 297 mm) 478230 A7 B7 V. Description of the invention (5) (Please read the precautions on the back before filling (This page) T 2 transistors T 4 and T 5 matched to the driving voltage V cc have the same impedance and idle or no-load voltage (loading equivalent), so that the input transistors T 1 and T 2 can It operates in its active area, that is, under unsaturation and the voltage from its collector to its base has always remained positive. Therefore, the current mirror transistors T 4 and T 5 can be replaced by a resistor coupled between the collector of the transistor and the positive supply voltage | V⑺. A simplified embodiment of an input sink, some of which are systematic and include only the main components in the text, are shown in Figure 2. Here, transistor T 3 is a current generator I 1, and on the other hand, input transistor T 1 And the collector of T 2 is only connected to the nodes indicated generally as shown. The principle of the output signal of the circuit shown in Fig. 1 and Fig. 2 is the collector current through any one of the input transistors T1, T2. An example of a voltage representing this current may be the current flowing in or out of the terminal 7 of the collector electrode of the second input transistor T 2. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs When the voltage between input terminals 1, 3 is a low value, the two input transistors T1, T2 are active and current flows from their emitter terminals to the common emitter node 5. And the current flowing through these transistors is determined by the current source I 1 or transistor T 3, respectively, and is disturbed in this way so that more current passes through the input transistor so that its input terminal, that is, the base, has the highest voltage. When the voltage between the input terminals becomes quite large, it means that the voltage is approximately equal to V τ, where V τ is proportional to the absolute temperature, and V τ is about 26 millivolts at room temperature. The current through the input transistor has the lowest potential at its input terminal. It can be ignored and the potential of the input terminal of the base or other input transistor is determined by the saturation current value of a transistor. The voltage between the base and the emitter of this transistor is approximately saturated. 8- This paper size applies the Chinese National Standard (CNS) A4 (210 X 297 mm). Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 478230 A7 B7_ 5. Description of the invention (6) In vBE = vr · logd / is), where I i is the current generated by the current generator 11 and I s is the saturation current of the transistor. It is assumed that when the voltage at the first input terminal 1 of the first input transistor T 1 is a very low value, the current at the input terminal 3 of the second input transistor T 2 is maintained at a constant value. The voltage of the first input transistor T 1 will be further reduced by one until the voltage of the emitter node is determined by the current of the current generator I 1 and the saturation current I s of the input transistor. When the voltage is further reduced, the P N-junction between the base and the emitter in the first input transistor T 1 will be biased forward to a very small and small range so as to be a reverse-bias. When the voltage finally becomes negative, the current will flow through the emitter of the first input transistor again but it is now in the opposite direction and depends on the value of the breakdown breakdown voltage of the PN-junction, and then all this A current flows through the first input terminal, that is, the base of the first input transistor T 1. At this time, the current is no longer determined by the current source I 1, but by the resistance of the external voltage source driving the capacitor and the two input transistors T 1 and T 2. In any case, the current can destroy the two input transistors T1, T2, but it is possible that the initial first transistor T1 will cause the largest amount of electrical energy. The voltage of an NPN transistor between reverse-biased P N-junctions varies between its emitter and base due to different manufacturing processes and different component plans, resulting in different on-current changes. For signal processing transistors, this current is generally higher than about 6 volts and lower than about 10 volts. Generally, a bipolar transistor includes three regions positioned in an array with each other and often includes layers disposed on top of each other. The bipolar transistor is made of semiconductor material to have a polarity of exchange, so that there is an intermediate layer region and two external regions. A bipolar transistor may be of the NPN or PNP type. Available from each region_9_ This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) ------------------ Order * ---- ---- (Please read the precautions on the back before filling this page) 478230 A7 B7_ V. Description of the invention (7) (Please read the precautions on the back before filling this page) There is also a circuit connection called electrode. The middle region is called the base and the two outer regions are called the emitter and collector respectively. If the voltage applied to the NPN transistor terminal makes the NPN transistor V. > Vb > Ve and the PNP transistor and get V (< Vb < Ve. Here V. 'Vb' Ve is the potential of each collector, base, and emitter of the transistor, sent to the base When the current is not too large, it should be positive for an NPN transistor and negative for a PNP transistor. The collector current flowing through the transistor is controlled by the value of the base current. In summary, the collector current is proportional to the base The current is proportional to the constant called BF, and the "forward current gain" is shown as 0. Arbitrarily, one of the two outer regions of the bipolar transistor is called the emitter and the other is the collector of the crystal. How, the ordinary collector and emitter are limited so that the proportional constant / 3 becomes larger. It is better. The applied voltage is the same polarity, such as the transistor inversion so that the collector is positioned where the original emitter is located. Obtain a consistent proportional constant or current gain factor, "reverse current gain". Usually BF is larger than BR. This fact is related to several choices of transistor architecture or planning. In this selection consideration, BF is required to have The larger the better, the gain should probably be the highest value. The value of BR is more than Not important, generally BF value = 50-100 and BR = 0.5-10. The important point to note is that the gain of using a transistor current in the amplifier circuit under obvious conditions should be greater than 1. Employees of the Bureau of Intellectual Property, Ministry of Economic Affairs A NPN transistor in a printed printed circuit of a consumer cooperative. A more common embodiment is a vertical transistor. The cross-section shown in Figure 3 is shown. Some external materials have the same as the base type. Low doping provides a layer to form a part or region of the transistor. The collector 13 is the lowest layer with the opposite doping of the outer layer material. Another layer 15 is positioned in the middle of the lower layer to form the base, in the middle of the base region -10- This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 478230 A7 B7_ V. Description of the invention (8) There are still layers 1 7 formed Poles, so that the structure sequence obtained in the middle includes the collector, base, and emitter from the bottom up. The outer ends of different areas up to the surface of the structure are used for external electrical connections. This type of transistor makes it complicated. Bit The quasi-decreasing order of emitter-base-collector, that is, the doping of the emitter region is higher than that of the base region and the doping of the base region is higher than that of the collector region. More recently, the middle base of the architecture The electrode layer 15 is very thin and the collector layer is relatively thick. This method provides the required characteristics including high current gain factor BF and excellent high frequency characteristics. When the collector-base-connection is an inverse-bias Also, the same characteristics of the breakdown breakdown voltage BVeb can be obtained. When the emitter-collector-connection is reverse-biased, it becomes a value larger than the breakdown breakdown voltage BVeb. It has been fully utilized in the manufacturing process. Therefore, the breakdown breakdown voltage between the collector and the base is often 50-120 volts, and the breakdown breakdown voltage BVeb at the emitter-base connection is relatively 6-12 volts. This manufacturing process used in the application enables the circuit to withstand higher voltages, such as the requirements for audio amplifier circuits, voltage converters for vehicle electronic circuits, and the like. The previously known way of protecting the input sink is as described above. In accordance with Figure 3, the resistors R 1 and R 2 are connected to the input terminals in series with the base terminals of the transistors T 1 and T 2. Therefore, the base current is limited. The diodes D1 and D2 are connected between the emitter and the base of the diode, so that the diode is in a direction opposite to the base-emitter-diode in each transistor. Continuity. Therefore, when the reverse voltage between the emitter and base of one of the transistors T 1 and T 2 exceeds the forward voltage of the external diodes D 1 and D 2 connected in antiparallel, the forward voltage is about 0.6 to 1 volt, the current is turned on by the original transistor -11-This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) ----------- I -------- Order --------- (Please read the precautions on the back before filling out this page) 478230 A7 B7_ V. Description of the invention (9) (Please read the precautions on the back first Fill out this page again) instead of conducting through an external diode. The advantages of this type of circuit solution include the protection element being input in normal operation only because the added protection element transconductance is not affected. The fabrication of such integrated circuits is known, as shown in Figure 5a. When only the transistor can be obtained in the manufacturing process, the diode can be obtained by interconnecting the base and collector of an transistor. Since there are two PN-interfaces in a transistor, it is obvious that a component can also obtain the function of a diode when the base and emitter of the transistor are connected to each other, as shown in Figure 5b. In any case, this diode is rarely used because it has worse characteristics when compared with a diode obtained by interconnecting the collector and base of a transistor in some applications. . Obviously, it is possible to use a bipolar transistor in a non-conventional way to obtain the protection of a differential amplifier input terminal as described above. As mentioned above, in most cases, a transistor can Get a high current gain. Such applications are no longer necessary as mentioned below. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. Figure 6a shows the principle circuit diagram of a differential amplifier. Its structure is completely the same as that of Figure 1 and Figure 2 with the input terminal protection amplifier. A more complete circuit is shown in FIG. This circuit solution has two NPN transistors, T 6 and T 7, connected between the emitters of the input transistors T 1 and T 2 and between the common emitter nodes 5. This transistor has its base terminal connected to the respective emitter terminal so that only the base-collector-diode is used. This connection allows the emitter in normal operation of the amplifier to have a higher potential than the collector-base, i.e., the base-collector is biased forward. If the same method has been discussed previously, the input voltage on the base 3 of the second input transistor T 2 is maintained at a fixed value when it is on the other input terminal 1, that is, 12- CNS) A4 specification (210 X 297 mm) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 478230 A7 B7 V. Description of the invention (1Q) When the voltage on the base of the first input transistor T 1 gradually decreases, it continues to flow The current through the first transistor is reduced to zero. Further reduction of the input voltage and current will flow in the "reverse direction" of the first transistor T1 from the emitter to the base, and it will now begin to flow until the voltage between node 5 and input terminal 1 exceeds the transistor T The sum of the breakdown breakdown voltage BVeb between the emitter and the base of 1 and the protection transistor T 6 is the sum of the breakdown breakdown voltage BVee between the collector and the emitter, and the breakdown breakdown between the collector and the emitter in a transistor The voltage can be considered, that is, most of the time, it is larger than the breakdown breakdown voltage BVeb between the emitter and the base in the same transistor, and further to the same extent as the above, such as the breakdown breakdown between the collector and the base. Breakthrough voltage BVcb. According to the solution of the protection circuit of Fig. 4, when the voltage between the node 5 and the output terminal 1 exceeds the breakdown breakdown voltage BVeb between the emitter and the base of the input transistor, a current surge of the input transistor T 1 has occurred. Fig. 6b is a main circuit diagram of a differential amplifier similar to Fig. 6a, in which the NPN transistor is replaced with an amplifying or movable two element and a protection element. The operation of this circuit is basically the same as that shown on the circuits of Figures 6a and 7. The advantage of solving the circuit according to Figs. 6a and 7 or Fig. 6b is that the circuit can tolerate higher voltages many times compared to the case without protection elements. Compared with the known circuit solution according to the figure, there are two advantages. In the known solution, when the current passes through the protection elements R1, R2, D1, and D2 during the protection operation, this uncontrolled current has the result of overheating. The solution according to Fig. 6a and Fig. 7 does not. Furthermore, resistors are not suitable for integration due to the fact that they are not suitable for manufacturing resistors in their own manufacturing process and because of the fact that resistors occupy a large area on circuit boards. -13- This paper size applies to China National Standard (CNS) A4 specifications (210 X 297mm) ------------ Installation -------- Order --------- (Please read the precautions on the back before filling this page) Revised Page of Chinese Specification for Patent Application No. 89107592 (January 91) A7 B7 jf 11 V. Description of the invention (in a single lithium integrated circuit. In a integrated circuit, the larger the resistance value, the longer the resistance. Since the width of the resistance has been The size cannot be reduced due to mass production limitation, and cannot be reduced due to visual solutions, and the ratio of the length and width in the resistor is determined. The resistor has a higher resistance value and can have a longer and larger area. According to Figure 4 In some cases, the protection circuit, resistors R1, R2, have other components not shown in the circuit, so that the power generated by the input terminals of the amplifying circuit may become very large. According to Fig. 6a, 6b and 7 Circuits such as diodes T 6 and T 7 have poor influence The transconductance of the amplifier. This may have advantages and disadvantages. Therefore, in some previously known circuits, a resistor can be used to protect the transistor T6 and T7 to reduce the value of transconductance. Symbol Description 1 '3 Input terminal 17 Layer 5 Emitter point ΊΠ, T2, T3 transistor 7 Terminal T4, T5 Current mirror circuit 11 External material T6, T7 transistor 13 Collector -14 This paper standard applies to China National Standard (CNS) A4 specification (210 X (297 mm)